|
Corresponding author: Jorge Luiz da Silva ( jorge.silva@blv.ifmt.edu.br ) Academic editor: Gabriel L. F. Mejdalani
© 2020 Jorge Luiz da Silva, Ricardo José da Silva, Izaias Médice Fernandes, Wesley Oliveira de Sousa, Fernando Zagury Vaz-de-Mello.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Silva JL, Silva RJ, Fernandes IM, Sousa WO, Vaz-de-Mello FZ (2020) Species composition and community structure of dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) compared among savanna and forest formations in the southwestern Brazilian Cerrado. Zoologia 37: 1-12. https://doi.org/10.3897/zoologia.37.e58960
|
Although dung beetles are important members of ecological communities and indicators of ecosystem quality, species diversity, and how it varies over space and habitat types, remains poorly understood in the Brazilian Cerrado. We compared dung beetle communities among plant formations in the Serra Azul State Park (SASP) in the state of Mato Grosso, Brazil. Sampling (by baited pitfall and flight-interception traps) was carried out in 2012 in the Park in four habitat types: two different savanna formations (typical and open) and two forest formations (seasonally deciduous and gallery). A total of 5,400 individuals collected comprised 57 species in 22 genera. Typical savanna had the greatest species richness and abundance, followed by open savanna and deciduous forest, while the gallery forest had the fewest species but high abundance. Tunnelers (one of three main nesting behavior guilds) showed the greatest richness and abundance (except in the gallery forest, where one dweller species was extremely abundant) in all plant formations. We found that species richness and abundance of the dung beetle community are influenced by differences among plant formations. Habitat heterogeneity in the different plant formations along with anthropic influences (fire, habitat fragmentation) are cited as important factors that explain guild and species richness and distribution patterns. These results emphasize the importance of protected areas, such as SASP, for the maintenance and conservation of species diversity in the Brazilian Cerrado.
Beetle community, guilds, habitat structure, inventory, RAPELD, Serra Azul Park
Dung beetles, found world-wide, are extremely diverse in the tropics (
Dung beetles can be divided into three main nesting behavior guilds (hereafter, simply “guild”) by the way they use the food resource: (1) rollers form balls of feces or carrion that they then roll and bury some distance from the source, (2) tunnelers bury feces or carrion at or very near the source, and (3) dwellers simply use the feces or carrion at the source without either tunneling or burying (
Assemblages of dung beetles respond quickly to habitat structure (
Landscape-wide variation in community structure is a consequence of adaptive response by dung beetles to different formations, such as open and dry savanna versus shady and humid forest. For example, differences in food resources and microclimate conditions for exploitation of feces (
The Brazilian savanna (locally known as Cerrado) occurs in much of the center of Brazil, where soils, geology, climate, and vegetation (forests, savannas, and grasslands) are all quite variable, resulting in a variety of savanna formations (
Here, we compare dung beetle community structure and composition among four vegetation formations (typical savanna, open savanna, deciduous forest, and gallery forest) in Serra Azul State Park (hereafter, SASP), a protected park in the state of Mato Grosso, Brazil. Specifically, we test how taxonomic and guild composition and structure are associated with vegetation formation in the study area. Based on the geographical location of the SASP and the predominance of savanna formations in its limits, we hypothesize that these habitats show high richness and abundance, and that the composition and guild structure vary according to the particular habitat types in which they are found.
We studied dung beetles in the SASP, in the state of Mato Grosso (15°51'S; 52°16'W), Brazil (Fig.
Map indicating the location of the study area within the Serra Azul State Park (SASP) in the state of Mato Grosso, Brazil. The detail illustrates the spatial organization of the plots following the RAPELD protocol. Plots 1, 7, 8, and 9 – Typical savanna, Plots 2, 4, 5, and 10 – Open savanna, Plot 3 – Gallery forest, Plot 6 – Deciduous forest.
Each 250 m transect was divided into 5 sampling points 50 m apart (the span of 200 m was within the 250 m). At each point, three pitfall traps were established at the angles of a triangle (each leg 3 m in length) centered on the point. Pitfalls were 19 cm diameter, 11 cm deep round plastic containers placed in the ground with the rim at the level of the soil surface. A roof to prevent pitfalls from filling with rainwater was built over each. A smaller recipient was placed at an edge of each pitfall to contain approximately 20 g of human feces used as bait. Beetle captures in the three pitfalls were combined to make each point a replicate, for a total of five sampling points per transect in ten transects. Two flight interception traps (FIT) were placed in each of the two savanna types, and one in each forest type, for a total of six traps. To preserve captured insects, approximately 250 ml of saline-detergent solution was placed in each pitfall and flight interception trap. After traps were open for 48 hours, trap contents were placed in 70% alcohol and transported to the laboratory at the Araguaia Campus of the Federal University of Mato Grosso. Dung beetles were identified to genus using the dichotomous key of
Community comparisons between plant formations included only captures from pitfalls, while captures from all traps were used in community-wide summaries of guilds and total species richness. We compared species diversity among the plant formations using sample-size-based rarefaction and extrapolation curves (
As the distance between samples within each plot is short and dung beetles are volant and search for resources, spatially close samples may show greater similarity in species composition than distant samples, causing spatial autocorrelation. To test for spatial autocorrelation of the dung beetle community we used Mantel correlogram (
In the case of important spatial autocorrelation, we used Distance-Based Moran's Eigenvector Maps (dbMEM) as a means of quantifying the spatial effect in spatial distribution of the dung beetles community. We used Euclidean distances and the function “dbmem” in the adespatial package (
To compare the community structure among plant formations [F] and control for the effects of spatial structure [S], and their interactions [F|S] (if any), we used PERMANOVA (
A total of 5400 dung beetles were collected, comprising 57 species, 22 genera and the following tribes: Coprini, Deltochilini (14 species each), Ateuchini (13 spp.), Phanaeini (12 spp.), Eurysternini, and Onthophagini (2 spp. each) (Table
The greatest number of species (47 spp., 82.45% of the total) and greatest abundance (1962 individuals, 36.33% of the total) were from typical savanna. Open savanna followed with 39 species (68.42%) and 1804 individuals (33.40%). Deciduous forest had 21 species (36.84%) and 256 individuals (4.74% of the total), while gallery forest had 18 species (31.57%) and 1378 individuals (25.51%), of which 1032 (74.89%) were of a single species, Eurysternus caribaeus (Herbst, 1789) (Table
Of the 47 species in the typical savanna, 12 were exclusive (25.53%), while in the open savanna, only three were exclusive (7.69%, Canthidiumsp. 27; Deltorhinum bilobatum Génier, 2010, Trichillum externepunctatum Preudhomme de Borre, 1886). Five species were exclusive in the two forests (Anomiopus sp. 4, Canthidium sp. 16, Canthon chalybaeus Blanchard, 1845, C. cyanescens, Oxysternon conspicillatum oberthueri Arnaud, 2002) (Table
Tunneling dung beetles were the most species-rich (29 species, 50.87% of the total), followed by rollers (12 spp., 21.05%), and dwellers (7 spp., 12.28%). Tunneling beetles were also the most abundant, with 2365 individuals (43.79% of the total), followed by dwellers (1842, 34.11%), and rollers (822, 15.22%). Nine species (371 individuals) could not be placed in any particular guild (Table
Sample-size-based rarefaction and extrapolation sampling curves (q = 0) of dung beetles collected with pitfall traps in the Serra Azul State Park (SASP), state of Mato Grosso, Brazil. The numbers in parentheses are the sample size and the observed Hill numbers for each reference sample. Shaded areas represent 95% confidence intervals.
Dung beetle species collected in the four plant formations in Serra Azul State Park (SASP) in the state of Mato Grosso, Brazil. (TS) typical savanna, (OS) open savanna, (DF) deciduous forest, (GF) gallery forest. Guilds: (T) Tunnelers, (R) Rollers, (D) Dwellers, (U) Unknown. (FIT) Flight interception traps. (*) Number according to reference collection of the Entomology Sector of the Zoological Collection of the Federal University of Mato Grosso (CEMT) in Cuiabá.
| Species | Savanna | Forest | Total | Guild | Method | ||||
|---|---|---|---|---|---|---|---|---|---|
| TS | OS | DF | GF | FIT | Pitfall | ||||
| Ateuchini | 201 | 228 | 15 | 35 | 479 | – | – | – | |
| Agamopus unguicularis (Harold, 1883) | 1 | 1 | R | 1 | |||||
| Ateuchus aff. histrio | 12 | 1 | 13 | T | 13 | ||||
| Ateuchus aff. pygidialis | 37 | 4 | 5 | 46 | T | 1 | 45 | ||
| Besourenga amarillai (Aguilar-Julio, 2001) | 1 | 3 | 4 | D | 4 | ||||
| Besourenga sp. 1* | 33 | 33 | D | 33 | |||||
| Deltorhinum bilobatum Génier, 2010 | 1 | 1 | U | 1 | |||||
| Genieridium bidens (Balthasar, 1942) | 4 | 11 | 15 | D | 15 | ||||
| Genieridium cryptops (Arrow, 1913) | 4 | 4 | D | 4 | |||||
| Trichillum externepunctatum Preudhomme de Borre, 1886 | 1 | 1 | D | 1 | |||||
| Uroxys sp. 1* | 78 | 104 | 1 | 17 | 200 | U | 36 | 164 | |
| Uroxys sp. 3* | 18 | 95 | 3 | 116 | U | 116 | |||
| Uroxys sp. 10* | 7 | 6 | 18 | 31 | U | 2 | 29 | ||
| Uroxys sp. 13* | 13 | 1 | 14 | U | 14 | ||||
| Coprini | 652 | 385 | 70 | 227 | 1334 | – | – | – | |
| Canthidium aff. barbacenicum | 191 | 89 | 4 | 284 | T | 37 | 247 | ||
| Canthidium aff. viride | 34 | 34 | T | 34 | |||||
| Canthidium decoratum (Perty, 1830) | 116 | 7 | 123 | T | 12 | 111 | |||
| Canthidium sp. 16* | 7 | 3 | 10 | T | 4 | 6 | |||
| Canthidium sp. 23* | 19 | 27 | 2 | 48 | T | 1 | 47 | ||
| Canthidium sp. 27* | 2 | 2 | T | 2 | |||||
| Dichotomius aff. carbonarius | 14 | 13 | 47 | 206 | 280 | T | 81 | 199 | |
| Dichotomius aff. cuprinus | 1 | 2 | 3 | T | 3 | ||||
| Dichotomius aff. depressicollis | 2 | 1 | 3 | 16 | 22 | T | 1 | 21 | |
| Dichotomius bos (Blanchard, 1846) | 14 | 62 | 76 | T | 76 | ||||
| Dichotomius lycas (Felsche, 1901) | 118 | 57 | 5 | 180 | T | 6 | 174 | ||
| Dichotomius nisus (Olivier, 1789) | 1 | 1 | T | 1 | |||||
| Ontherus appendiculatus (Mannerheim, 1829) | 108 | 116 | 4 | 228 | T | 228 | |||
| Ontherus dentatus Luederwaldt, 1930 | 34 | 9 | 43 | T | 43 | ||||
| Deltochilini | 287 | 491 | 7 | 42 | 827 | – | – | – | |
| Anomiopus sp. 2* | 2 | 2 | U | 2 | |||||
| Anomiopus sp. 3* | 1 | 1 | 2 | U | 1 | 1 | |||
| Anomiopus sp. 4* | 2 | 2 | U | 2 | |||||
| Canthon aff. simulans | 28 | 364 | 392 | R | 18 | 374 | |||
| Canthon chalybaeus Blanchard, 1845 | 1 | 2 | 3 | R | 2 | 1 | |||
| Canthon fortemarginatus Balthasar, 1939 | 171 | 54 | 225 | R | 3 | 222 | |||
| Canthon histrio (Lepeletier de Saint-Fageau & Audinet-Serville 1828) | 1 | 18 | 2 | 11 | 32 | R | 5 | 27 | |
| Canthon lituratus (Germar, 1813) | 30 | 1 | 31 | R | 31 | ||||
| Canthon sp. 3* | 1 | 1 | R | 1 | |||||
| Canthonella sp. 3* | 1 | 14 | 15 | R | 15 | ||||
| Deltochilum enceladus Kolbe, 1893 | 2 | 2 | 1 | 22 | 27 | R | 9 | 18 | |
| Deltochilum pseudoicarus (Balthasar, 1939) | 2 | 2 | 4 | R | 1 | 3 | |||
| Deltochilum sp. 6* | 39 | 35 | 3 | 4 | 81 | R | 38 | 43 | |
| Malagoniella aeneicollis (Waterhouse, 1890) | 10 | 10 | R | 10 | |||||
| Eurysternini | 331 | 357 | 60 | 1037 | 1785 | – | – | – | |
| Eurysternus caribaeus (Herbst, 1789) | 8 | 8 | 17 | 1032 | 1065 | D | 61 | 1004 | |
| Eurysternus nigrovirens Génier, 2009 | 323 | 349 | 43 | 5 | 720 | D | 9 | 711 | |
| Onthophagini | 125 | 212 | 88 | 19 | 444 | – | – | – | |
| Onthophagus aff. hirculus | 50 | 38 | 87 | 19 | 194 | T | 194 | ||
| Onthophagus buculus Mannerheim, 1829 | 75 | 174 | 1 | 250 | T | 250 | |||
| Phanaeini | 366 | 131 | 16 | 18 | 531 | – | – | – | |
| Coprophanaeus acrisius (MacLeay, 1819) | 2 | 4 | 6 | T | 5 | 1 | |||
| Coprophanaeus cyanescens d'Olsoufieff, 1924 | 4 | 4 | T | 4 | |||||
| Coprophanaeus spitzi (Pessôa, 1934) | 6 | 6 | T | 5 | 1 | ||||
| Dendropaemon denticollis Felsche, 1909 | 2 | 1 | 3 | U | 2 | 1 | |||
| Diabroctis mimas (Linnaeus, 1758) | 16 | 13 | 2 | 31 | T | 1 | 30 | ||
| Diabroctis mirabilis (Harold, 1877) | 2 | 2 | T | 2 | |||||
| Oxysternon conspicillatum oberthueri Arnaud, 2002 | 9 | 13 | 22 | T | 11 | 11 | |||
| Oxysternon palemo Castelnau, 1840 | 284 | 106 | 390 | T | 10 | 380 | |||
| Oxysternon silenus Castelnau, 1840 | 1 | 5 | 1 | 7 | T | 1 | 6 | ||
| Phanaeus kirbyi Vigors, 1825 | 3 | 3 | T | 1 | 2 | ||||
| Phanaeus melibaeus Blanchard, 1846 | 1 | 1 | T | 1 | |||||
| Phanaeus palaeno (Blanchard, 1846) | 49 | 7 | 56 | T | 5 | 51 | |||
| Richness | 47 | 39 | 21 | 18 | 57 | – | 32 | 54 | |
| Richness % | 82.45 | 68.42 | 36.84 | 31.57 | – | – | 56.14 | 94.73 | |
| Abundance | 1962 | 1804 | 256 | 1378 | 5400 | – | 377 | 5023 | |
While in the gallery forest, where one dweller species (E. caribeus) comprised 74.89% of the individuals collected, the two savanna formations were more similar and had no strongly numerically dominant species (Fig.
Rank abundances of dung beetles compared among the four plant formations in the Serra Azul State Park (SASP), state of Mato Grosso, Brazil. The letters indicate the more abundant species: (A) Eurysternus caribaeus, (B) Dichotomius aff. carbonarius, (C) Onthophagus aff. hirculus, (D) Eurysternus nigrovirens, (E) Canthon aff. simulans, (F) Onthophagus buculus, (G) Oxysternon palemo, (H) Canthon fortemarginatus, (I) Canthidium aff. barbacenicum.
The Mantel Correlogram indicated that spatial autocorrelation existed. At the first distance class (i.e., 29.06 to 471.63 m), the correlation was strongest and positive (r = 0.37, p = 0.001), and weaker and negative (r = -0.20, p = 0.001) at the second distance class (i.e., 471.63 to 914.63 m). Thus, spatial autocorrelation was found at less than 914 m (Fig.
The two first PCoA axes explain ~51% of the variation in the dung beetle community and separate the two savannas from the two forests (Fig.
Mantel correlogram between dung beetle community and pairwise distance of plots in the four plant formations of the Serra Azul State Park (SASP), state of Mato Grosso, Brazil. Positive significant values indicate a positive autocorrelation, while significant negative values have the opposite interpretation. Significant values are represented by red circle.
Dung beetle communities are more species-rich and species are more abundant in the savanna as compared to forest formations in the SASP. In addition, species composition and guild structure varied between the two formations. Dung beetles are diverse in the Brazilian Cerrado (mostly savanna, but within which are patches of gallery and dry-deciduous forests, much like those we examined here), where savanna formations tend to be more diverse and species-rich than forests (
The SASP is in a region where dung beetles are common and diverse (southwestern Brazilian Cerrado). For example, Besourenga amarillai (Aguilar-Julio, 2001), Canthidium barbacenicum Preudhomme de Borre, 1886, Canthidium decoratum (Perty, 1830), C. aff. simulans, Canthon fortemarginatus Balthasar, 1939, Dichotomius lycas (Felsche, 1901), E. nigrovirens, Genieridium cryptops (Arrow, 1913), Onthophagus buculus Mannerheim, 1829, O. palemo, and Phanaeus kirbyi Vigors, 1825 are often found in open (natural or anthropic) landscapes in central South America (in the Cerrado and Chaco formations;
Most species captured in all habitat types were tunnelers, followed by rollers and dwellers, a result that appears to be the general pattern for dung beetles in the Neotropical region (
Both rollers and dwellers are also more abundant and species-rich in the savanna formations, with the exception of the dweller E. caribaeus, which was super-abundant in the gallery forest. This is surprising because the more humid environment of the forest is expected to generate microclimates that favor these guilds because feces should dry more slowly (
No single species was dominant in the savanna formations where two or more species tended to be similarly abundant, in contrast to the forests, especially gallery forest. Dominance has been found in some dung beetle assemblages in both savannas and forests (
Some spatially structured processes may also influence local species compositions in dung beetle communities (
Although the SASP is a protected area for conservation, anthropic pressures, such as forest fires, can influence habitat structure and availability, thereby influencing the dung beetle community. For example, forest fires occurred in 2002, 2005, and 2007, when the entire Park burned (
Considering the history of SASP occupation and its surroundings, deforestation is cited as one of the most important anthropic pressures on the Park (
We consider that this regional landscape mosaic, formed by combinations of forests and savannas of the Brazilian Cerrado, has been an important determinant of the dung beetle communities found in the SASP. For these reasons, regional diversity is very high. We believe that additional measures are necessary for protecting the SASP. These measures should take into account the complex matrix of habitat types and species that occur in each of these habitats (
FZVM is funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq – processes 304925/2010-1, 302997/2013-0, 405697/2013-9, 306745/2016-0, 431760/2018-7) and Fundação de Amparo à Pesquisa do Estado de Mato Grosso (FAPEMAT, Edital Universal 005/2012 process 328959/2012, PRONEM 568005/2014, FAPEMAT 0147956/2017). Support also came from the INCT-INAU/CNPq, INCT-CENBAM/CNPq, RedeComCerrado, the SISBIOTA Project (CNPq process 563134/2010-0) and the PPBIO Project (CNPq process 457497/2012-2).We sincerely thank the referees for their critical reading of and suggestions for improving the manuscript. James J. Roper, translated the text from the Portuguese.